It is known, e.g. from British Pat. No. 30,487 of 1909, to form each end face of the outer race of such a bearing with an undercut annular recess and forcing an outwardly bulging annular washer into each recess; upon subsequent flattening, the washer extends radially to the immediate vicinity of the inner race whereby the intervening clearance is substantially closed against the outside. This arrangement, while being theoretically satisfactory, requires very close tolerances and is therefore difficult to realize in practice.